If there is a link posted on Facebook to my website, and a user follows it, I would like to display custom content using PHP. I tried with the following method...
$_SERVER['HTTP_REFERER']
Facebook must block this feature because it is not working. Is there a method for this that actually works with Facebook?
This news is a year old, yet I see they are still using it.. I post it here because It is still pretty informative The srouce of the link is https://www.facebook.com/note.php?note_id=10151070897728920
Restricting the Referrer
We still need to let the websites you navigate to know the traffic is
from Facebook, but we also want to prevent them from reading the full
source url. Otherwise, they could know where on the site you were when
you clicked their link. In order to strike this balance, we've taken
advantage of a new feature called the meta referrer, currently
available in Chrome 17+ and Safari 6+. This allows us to specify how
much of the source url to share with the external site via the Referer
header. If you're using one of these supported browsers you can take
advantage of this new feature. Otherwise, your browser will be routed
to the slightly slower older system.
This change should reduce the impact of the link shim on your browsing
(especially when accessing Facebook from a cellular network) and
should help save around a second for a typical user.
Related
I am not sure this is correct SO to post on, but if not admin please feel free to move it to relevant SO or suggest me to move it.
I am using a contractor to help me create a website for some project. He has coded the entire custom website in PHP.
One feature that I requested was that links posted on the website should have the preview feature that we see in Facebook (FB) like in attached picture.
But he keeps saying that I can only use embedded code to create such preview feature. When I show him the FB preview he says FB is probably using technology of its own. Currently if I post the link from youtube to my test website it shows up as text like: https://www.youtube.com/watch?v=jtkUtNzaFPI&t=1909s
My question is:
What exactly is FB using? Is this easy to implement for any PHP developer or is it really time consuming implementation.
"he says FB is probably using technology of its own"
His answer to your question is utter nonsense, and indicates only that he doesn't want to do what you're asking. You hopefully aren't paying him very much.
What Facebook is doing is kind of sneaky, but structurally simple. The order of operations is:
User enters text on Facebook page.
AJAX request is sent to Facebook server with text.
Facebook server parses and sees that there's a link in there.
Facebook server makes a server-side HTTP request to link destination to find out more.
Facebook server parses response for anything it can add to the input template that the user is seeing.
Facebook responds back to user (maybe web sockets? maybe a response to that earlier AJAX request?)
Client-side code on the Facebook page updates what the user is seeing.
Steps 2-6 intuitively sound like they may take a lot of network time, but these tend to be very quick services (Facebook itself, YouTube, etc.) so that's usually not a problem.
The main concern here are Step 3 and Step 5. That's where Facebook is using some custom logic that it likely spent considerable effort defining. There may be libraries which help with that, likely made in response to the demand for this exact feature. I don't have any to recommend, sorry.
The technical implementation is the easy part. Determining from the user's text what data to fetch could be difficult. Determining what data to put in the page could be difficult. That depends on the scope of what you want to implement.
For example, it may be difficult to detect if the user has entered a variety of things you can respond to, but it may be easy (with a regular expression perhaps) to detect if the user has entered what might be a YouTube URL. So if you reduce the problem space to just YouTube previews, then you may be onto something. If you can successfully parse that YouTube link, you're in business. Now you can hit a YouTube API and get information to send back to the page.
Continue with that pattern for other small problem spaces (previewing a link to an image, previewing a link for another popular site, etc.), and you can over time add that same feature.
I have written a PHP based blog for the company i work for. Not using any frameworks. I am having trouble tracking users who come from my facebook page's posts to my blog (not wordpress).
I have created a shortlink url. Let's say it is sample.co and it redirects traffic to sample.com. Everything seems fine until here. The problem starts here.
I am adding all user's ip's, user agents. But if even i get 500 visits, my code adds somethig like 3.000 visits. Facebook stats and Analytics shows similar stats (~500 visits). I see that ip's added to MySQL are all different. It usually happens with Android users. I have read somewhere that Facebook sometimes renders to their users the actual URL when FB shows the post. I mean instead of the widget, Facebook shows the whole page. I am not quite sure about that to be honest.
To solve this problem, I have created and added an jquery script to my page and listened users' scroll event. It worked great. Not seeing too much traffic. But this time the problem is i am counting less users. Even I get 500 users from facebook and Analytics shows similar results, my script adds only 200-300 to MySQL.
Does anyone know a better way to track real traffic? Or do you aware of such problem?
Thanks
It should be filtered on the basis of user agent.
https://developers.facebook.com/docs/sharing/webmasters/crawler
how to detect search engine bots with php?
Identifying users through IP is a good idea, but if your IP keeps changing, it's a good idea to use cookies.
http://php.net/manual/en/function.uniqid.php
If the cookie does not exist, you should see it as a new user.
I have found the answer. The problem is called preview (prefetch). Here is the link:
https://www.facebook.com/business/help/1514372351922333
Simply, facebook preloads everything when FB shows the thumbnail to the visitor to speed up your page's load speed. They send X-Purpose: preview header. So you can simply check if HTTP_X_PURPOSE header's value is preview or not. If so, do not count it as a visitor.!
Here are more detailed descriptions:
http://inchoo.net/dev-talk/mitigating-facebook-x-fb-http-engine-liger/
http://inchoo.net/dev-talk/magento-website-hammering-facebook-liger/
i have a website ,i promoted it by sharing it's link on facebook and Google +.
i want to know whether the visitor come from by clicking the link i share on facebook or from Google + or from google search etc.
i don't have any official deal with both facebook and Google+ for promoting my website.
my question is! is it possible by any way ?
Since the http referer ($_SERVER['HTTP_REFERER']) won't be set consistently and there will be the support of rel=noreferrer attributes on anchors soon, this could be tricky.
But since you are the one to share the links on social media, you could add a get parameter like:
myFancyDomain.com?referrer=facebook
This is the only consistent way I could imagine :)
I guess this is a good quote (even it's kinda old):
The "Referer" header entry is optional. You cannot rely on it being
present. There is no cross-browser way to get the previous link
because this depends on the user settings and proxy configuration
(i.e. what the system administrators think they should allow you to
see).
You must find a way to live without this information.
Source
Context
I'm running a site over https where new content (each entry has its own page) can be created and shared by users.
Each page has an image, and this image url is present in the og:image meta tag at the top of the page.
Problem
Facebook seems slow to pick up on the og:image. When the page is first created and a user attempts to share the URL, for the first ~1-3 tries, the og:image is not scraped / rendered by Facebook (the title and description are). Afterwards, the image is clearly visible in the share dialog.
A similar issue also occurs when using Facebook's OG URL debug tool. The first time I pop in the URL, it shows no image. If I choose to fetch the page from the source again, it shows the image.
Additional Notes
At first, I thought it might have been site code initially not showing the image, but I sent a curl request and spoofed one of Facebook's user agent strings (this is important to accessing the page) and the resulting HTML contains the og:image tag with the correct image URL. I also know it's not anything to do with accessing the page, or the og:title and og:description data would not be showing (but it is).
My only lead is that it could be an SSL or HTTPS issue. I recently set up the SSL certificate but I'm not sure why that would cause a delay over it not working at all.
For the sake of clarity, the site runs on WordPress on top of a standard LAMP stack.
The issue is apparently a fairly common one. The solution was to, on content creation, send a request to facebook's scraper tool with the content's URL. The scraper will pick up and process the image, allowing the first share to already have that image cached by Facebook.
Yes I've noticed this as well. It takes a long time for Facebook to cache the og:image. Tumblr does it automatically. The only reason why I could imagine why Facebook does this other than poor programming is because perhaps they have a review team scrolling through the thumbnails to block nudity and other crude images. As mentioned above, clicking the facebook share url manually upon creation will prompt them to cache it, hopefully before others click too.
I have been analyzing this issue one year ago. I had the same problem. The og:image meta tag has been only updated after several rescrape attempts.
This re-scraping can be easily triggered on this page https://developers.facebook.com/tools/debug/
According to my old analysis, the root cause of this behavior is that the FB scraper seems to have a very very short timeout. If the content page does not reply to the scraper request very quickly, FB doesn't take this reply into account. Even if the content page serves the correct meta data and a valid HTTP/200 reply, FB ignores it because "too late is too late".
I didn't find any solution for this besides "prescraping" as has been already described by Sean.
In My Case I had a azure WebApp with HTTPS setup without SSL Certificate installed. As It was in Production stage, I tested by reverting back to HTTP. All "og" tags were detected.
So, If your SSL is not properly configured and/or Facebook gives CURL SSL Error, looking into SSL might help.
I'm very confused so I hope that my question will make sense.
I'm working with the facebook API, and so far I've implemented login and a post to the users wall via php. I know read a bit more about the OpenGraph system, and the meta tags that you're supposed to put in your site, but I'm not quite grasping the concept og how to get my site fully PHP integrated with Facebook.
I have another login system which I've hooked facebook up to, so switching to javascript only will not be an option. Do the meta tags even matter if I use PHP only. I mean, I can't really get my head around how the token and all of that would be interpreted alongside the og: metatags if there is no javascript on the site.
Can I have BOTH php and javascript authentication? What's all that fuzz about opengraph anyway?
These are my thoughts about working with facebook, and if you'd like me to summarize this up in one question I guess it'd be:
How do I benefit from the opengraph meta tag features (tracking the users, in their timeline) when I'm only connected via PHP?
I'm confused about how the tags for specific open graph actions get interpreted like
<meta property="fb:app_id" content="xxxxxxxxxx" />
<meta property="og:type" content="myapp:read" />
and then it's supposed to post "MyName is reading lalala" or "MyName read lalala". How's the post to the server going on (if people have already authenticated via php):) ?
Unless I am misunderstanding your question, I think you are confusing how the Open Graph meta tags work. The meta tags provide external websites with exactly what they say: meta information, to be read by Facebook's "crawler". Facebook has their own web crawler that will grab certain relevant information about a webpage (for example, page title, page description, an image to associate with a webpage) so that Facebook can use that info when people "Like" or "Share" a webpage.
For example, going to https://www.facebook.com/sharer/sharer.php?u=http://example.com should illustrate how the crawler works: when someone tries to share the URL example.com on Facebook, Facebook's crawler goes to the example.com webpage and grabs relevant info, then displays it on their own page to allow you to share it with others.
The open graph tags have little or nothing to do with authenticating a user or application on Facebook's servers. They can be used totally independently of any login system that you have in place, as far as I know. All they do is provide meta information about a web page to Facebook's web crawler.
I understand your frustration with Facebook's API though - they are notoriously bad about keeping detailed, accurate information, and they change the API so frequently it's nearly impossible to keep up.
I can confirm that you're not the only one to be frustrated with the Facebook Documentation.
With that being said, i'll try to help you. As Sean said, the og graph tags have little or nothing to do with your authentication flow.
These are featured as information of what the user is doing at a certain time, like listening to a song, playing to one particular game, etc...
The Facebook's PHP SDK provides you functions to create your own objects and actions. Then you can call a $facebook->api(/...) function to indication to Facebook : My user is ACTIONS an OBJECT. Doing this, you must provide a parameter, which is the URL of the OBJECT on your Website/Application. In fact, Facebook wants you to tell him where he can finds what's this object. On a page where there's the correct meta-tags corresponding to this object ! Here are your og tags.
As you said, this will provide stories found in the timeline, or the ticker. It's those kind of things that Facebook Games use, "X is playing to Y", "Z earned the Grand Master title by playing on A", etc...
You must define those objects on your Facebook Applications Panel, and have the corresponding meta-tags on your website.
Then you just have to make the $facebook->api(/...) (or equivalent) request when this action happens on your website/application !
Everything is almost entirely explained in this tutorial : http://developers.facebook.com/docs/beta/opengraph/
Hope this will help you to find an answer.